1. Field of the Invention
The present invention relates to an optical transmitter, in particular, the invention relates to an optical transmitter with stable output wavelength applicable to a wavelength division multiplexing (WDM) system.
2. Related Prior Arts
An optical transmitter implemented with a semiconductor laser diode (hereafter denoted as LD) has been well known and applied to the WDM system. A United States Patent, the U.S. Pat. No. 7,899,337, has disclosed an optical transmitter with a function to increase an output thereof stepwise to a target level.